Micronor now offers a complete range of discrete (contact type) fiber optic temperature sensors, probes and interfaces for temperature measurement in challenging environments. TS series fiber optic temperature probes offer immunity to RF and microwave radiation along with wide temperature range, intrinsic safety and non-invasive use. The fiber optic temperature probes can operate over -200°C to +300°C (-328°F to +572°F), and withstand harsh and corrosive environments. Typical fiber optic temperature monitoring applications include:
- Process monitoring
- Power transformers
- Medical environments
- Catheter instrumentation
- Harsh chemical conditions, including radiation environments.
The TS series fiber optic temperature probes are true absolute temperature sensors consisting of a gallium arsenide (GaAs) crystal that is mounted on the end of an optical fiber. The block diagram above illustrates how the fiber optic temperature measurement system works. A broadband light source is coupled into the fiber and impinges on the crystal. GaAs behaves like a temperature sensitive cut-off filter in which the crystal absorbs some light and transmits other light. The characteristic edge, or transition wavelength, between the reflected and transmitted spectrum is directly related to the band gap energy, and hence the absolute temperature.
Technical Explanation: The system records the photo energy sufficient to excite an electron from the valence to the conduction band of the semiconductor crystal. The required amount of energy is equal to the so-called band-gap energy, Egap. The well-known underlying principle of operation is based on the temperature dependence of the band gap of the direct (zone center) GaAs intrinsic gap; Egap=1.423eV, corresponding to 872nm at 300°K; dEgap/dT= -0.452meV/°K at 300°K. The spectrum of a GaAs sensor crystal placed in a medium of unknown temperature is measured in the reflectance mode, and the wavelength position of the characteristic edge is analyzed to determine the temperature.
Download this technical paper for more information about how GaAs fiber optic temperature sensors work and their features: A New Fiber Optical Thermometer and Its Application for Process Control in Strong Electric, Magnetic, and Electromagnetic Fields, SENSORS LETTERS, 2003
Select the TS temperature sensor best suited for your application:
- TS2, for general purpose R&D, power transformers and industrial applications
- TS3, for general purpose R&D, RF and microwave applications
- TS4, for harsh chemical and nuclear conditions
- TS5, for medical applications and where smallest profile required
- TS Trafo, for oil-filled transformer applications
- TS Multipoint, for special bundled probe applications
- TS Nano, for OEM self-assembly applications
FOTEMP Signal Conditioners come in a range of form factors – Handheld, Bench Top, DIN Rail, Rack Mount, OEM PCB and OEM Module.